Puhelin teollisuus wall phone
This is Finnish made telephone, from OY Puhelinteollisuus (Telephonefactory) in Helsinki.
Wiring inside the casing (no date or type unfortunately), casing made from birch and birch plywood.
Phone may be done during 1950's.
O/Y Puhelinteollisuus was founded 20.09.1940 and name changed to Standard Electric Puhelinteollisuus OY 19.04.1962. Name changed again 19.06.1991 to Algatel Suomi OY and closed 31.05.2007.